[ADD]IoT : flash_sdcard

iot.rst

@@ -10,3 +10,4 @@ Internet of Things (IoT)
    iot/connect
    iot/pos
    iot/iot_notfound
+   iot/flash_sdcard

iot/flash_sdcard.rst

@@ -0,0 +1,22 @@
+=====================
+Flashing your SD Card
+=====================
+
+In some case, you may need to reflash your IoT Box’s SD Card to benefit
+from our latest updates.
+
+Updating your SD Card with Etcher
+=================================
+
+Go to Balena’s website and download
+`Etcher <http://wwww.balena.org>`__, It’s a free and
+open-source utility used for burning image files. Install and launch it.
+
+Now, download the latest image `here <http://nightly.odoo.com/master/posbox/iotbox/>`__, and extract it from the zip file. Then, open *Etcher* and select the image.
+Select the drive to flash (where your SD Card is) and click on
+*Flash*!.
+
+Now, your image will be automatically updated. You just have to wait 5 minutes for it to finish.
+
+.. image:: media/flash_sdcard01.png
+   :align: center